1. Technical Field
The present invention relates to fluid dispensation methods whereby a predetermined quantity of a liquid is poured under a low-pressure environment into specific regions of mechanical and other devices. In particular the invention relates to methods of dispensing lubricating fluid into dynamic-pressure bearing devices employed in signal record/playback devices such as hard-disk drives.
2. Description of the Related Art
In order to carry out dosed infusion of a small volume of fluid into a targeted site, to date microdispensers have been employed. The simplest microdispensers are made up of a small-diameter nozzle, and a mechanism for sending fluids into the nozzle. Components constituting industrially employed microdispensers include a nozzle section, a mechanism that imparts delivery pressure to the fluid, a valve mechanism for controlling fluid outflow, and a mechanism that controls a series of dispenser actions.
Nevertheless, utilizing a microdispensers to accurately stream a predetermined volume of lubricating fluid into components or mechanical devices when placed under a vacuum is not necessarily a simple matter. The difficulty is that, different from applications in which dispensing is carried out under atmospheric pressure, under a reduced-pressure environment, despite shutting the valve in an effort to stop the infusion, the flow does not immediately cease. The reason it does not is because in contrast to the situation under atmospheric pressure, in which when the valve is shut the fluid is held back by the atmospheric pressure from flowing out any further, under a reduced-pressure environment that restraining force attenuates, such that the fluid continues, due to inertia, to flow out. In addition to attenuating the back pressure on the outflowing fluid, a reduced-pressure environment hastens the fluid outflow speed, such that the fluid vigorously strikes the infusion target object, as a consequence of which the fluid splatters in splashes, giving rise to such problems as the infusion volume falling short, and the fluid sticking to areas where it is not desired to have the fluid adhere.
In order to eliminate these sorts of troubles, a need to dispense the lubricating oil sufficiently slowly is brought about. This demand prolongs the time required for a single dispensation cycle, which impairs productivity.
Thus, an infusion method allowing a predetermined volume of a fluid to be accurately infused without contaminating the environs, and whereby productivity is high has not been known to date.